Ignition system



1,502,674 J. H. HUNT IGNITION SYSTEM Filed Now 18. 192a Q 2 7.5/116 co// 40 m6 co// o W 4/ 5/ 43 I s3 FL TIMER 30 Z aA TTERY v D/Sm/Bl/TOR f 7 BURNER SPARK PLUG l/V FUEL HEATER 25? 26 '27 E/va//viUi/:\RK

122755555 [UL/517701" 4 4W 4% 4% 5b A 7 Jana. 16. 2&7

Patented July 29, 1924.

UNITED STATES PATENT OFFICE.

JOHN H. HUNT, or DAYTON, 01110, AssIcNoR 'ro THE DAYTON ENGINEERING LABO- mrronms COMPANY, or nAY'romo-mo, A CORPORATION or 0310.

IGNITION SYSTEM.

Application filed November 18, 1920. Serial No. 424,836.

T a] lav-72.0122. it may concern:

Be It known that I, JOHN H. HUNT, a Cll'lZeIl of the United States of America,

residing at Dayton, county of Montgomery,

and State of Ohio, have invented certain new and useful Improvements in Ignition Systems, of which the following is a full, clear, and exact description.

This invention relates to ignition systems for internal-combustion engines, and particularly for engines of the automobile type.

The ignition systems for firing the explosive mixture within the cylinders of an.

internal-combustion engine are generally well known. Such a system includes a battery or other current source, an ignition coil, a timer for controlling the passage of current from the battery to the coil and a distributor for distributing the sparking impulses generated by the coil to the various spark plugs of the engine. In order to assist in starting the engine in cold weather and to assist in the operation of the engine on relatively low grade fuels, electrically ignited fuel burners have been provided for the purpose of heatin the combustible mixture before it passes into the engine. In order to employ the ignition system of an' internal-combustion engine in anignition system forboth the engine and burner and provided an apparatus which is economical and is effective at all ignition systems it has been found thatthe current in the primary windings must be substantially twice that-employed to opcrate an engine ignition system. This 1ncrease in current consumption draws heavily on the battery and causes excessive sparking at the timer contacts. It is anoth {object of'the resent invention to overc ge these difliculties. J

Other and further objects of the present invention will be apparent from the following description, references being had to the accompanying drawing, wherein a preis clearly shown.

The figure of the drawing is' a wiring diagram illustrating the present invention.

In the drawing, designates the ignition timer, which may be of the usual type including a pair of contacts 21 shunted by a condenser 22. 23 designates a distributor adapted to distribute sparking impulses to the various spark plugs of an engine designated by numerals 24, 25, 26 and 27. In the usualv type of ignition system for igniting the combustible mixture withinthe engine cylinders, the battery 30 would be connected in series with an ignition switch and with the primary winding and ignition coil and with the timer 20. The secondary winding of the ignition coil would be grounded preferably through the batteryand would be connected with the distributor 23.

In place of the usual ignition coil two coils, and 50, are provided. The primary circuit includes the primary windings 41 and 51 of these coils which are connected together in parallel and both together in series-with the battery 30, ignition switch '31 and timer 20. The high tension circuit includes the secondary Windings42 and 52 of these coils which are connected in series; and one end of secondary winding 42 is connected by wire 43 with the ignition distributor 23 and wire 53 connects the secondary winding 52 with spark plug 54 forthe purpose of igniting the combustible mixture of a fuel heater which. is not shown since it is not of itself a part of the invention. It is believed sufiicient for the purpose of understanding the present invention to state that the fuel heater includes a liquid fuel burner in which fuel is sprayed into a combustion chamber through a nozzle and is kept ignited by the spark chamber across the gap of the spark plug 54. In order that the fuel heater may burn properlyat all times it has been found preferable to make the spark gap 55 at the burner plug wider than the usual width of the spark gap of an engine spark plug 24.

Coil 40 has relatively small inductance and a relatively large transformation ratio,.' while the coil 50 has relatively great inductance and relatively small transformation ratio. In order to give some idea of suitable dimensions of coils which may be formation ratio of about 70 and an inducf tance of about 7,}- millihenrics. The primary winding 41 consists of 260 turns of No- 20 wire having a resistance of .62 ohm. The coil 50 has a transfori'nation ratio of 20 and an inductance of approximately 40 millihenries, and the primary winding 51 con: sists of 500 turns of No. 24 wire having a resistance of 2.72 ohms. It is to be understood, however, that these dimensions are given only by way of example and that the present invention is not limited thereto. These dimensions will vary according to the type of engine and burner used. I

In the operation of the system, when the timer contacts 21 close, current will flow from the battery through both primary windings 41' and 51. As the coil 51 has greater inductance than the coil 41, current will not build up as quickly in the coil 51 as in coil 41 and at the time the contacts 21 ,open, the current in coil 51 will usually have the smaller value. .Gurrent to be interrupted by the contacts 21 will not be excessive, and therefore'therewill not he undue ar'cingof the contacts to cause pitting or corroding of the latter. The operation of this ignition system on a relatively small amount of current is due to a large extent to the relatively high resistance and high inductance inthe primary winding of coil 50,- the high resistance cutting down the current flow at low engine speeds. It has been found that this ignition system can be operated effectively at all engine speeds on a current consumption which does not exceed the current consumption of an ordinary engine sys-' tem by more than 25%. This is in marked contrast to the operation of double end coils and similar devices in which the current consumption for the burner and engine ignition is substantially twice that used in the engine ignition system alone. The secondary windings {l2 and52 are so connected that the electromotive force generated'by these windings will be accumu ative in effect and will flow preferably in the direction of the arrow at the time the primary ignition circuit is interrupted. The combined voltages 'of these windings will be sufficient to jump both the engine spark plug gap and the burner spark plug gap.

The present invention can be used advantageously to provide ignition for an engine and its intake heater burner because it has been found that'less ignition secondary voltage is required after the burner becomes operative than when starting the burner into operation. Then the burner is hot the fuel 's'rayed intogit can be ignited by the "heate burner walls and electrical ignition is r equired only to insure keeping the burner lighted especially under conditions when the burner is subjected to jarring and vi bration incident to use in an automobile. It has been found that the burner flame provides a conducting path for the secondary current, the spark gap inthe engine cylinder being practically the only gap in the secondary circuit. It follows that after the engine is self-operative the secondary voltage need not be boosted to the extent required for starting the burner. The burner is startedv when the engine is cranked in order to assist vaporizing the fuel mixture. Since engine cranking speeds are relatively low, there is. time for current to be built up in primary 51 of coil 50 to an amount sufficient for generating a substantial voltage in coil 50 when the timer contacts open to cause the coil energy to be released. At higher speeds such as occur when the engine is self operative and the burner is hot, the current in primary 51 is limited to a relatively low amount by the high inductance of coil 50. Therefore as the demand for secondary voltage is reduced the boosting action is automatically reduced. This action tends towardeconomy of current and tends to .maintain the primary current within bounds suitable for the timer con- The ignition apparatus provides a booster coil having means for automatically reducing the boosting action and current consumption as the engine speed increases.

It has been found that the engine spark plug gap receives more energy than the burner spark plug gap at all speeds of operation of the timer. The energy received by both gaps is considerably higher at low speeds than at high speeds, and the energy the same proportion. This feature of the invention works to advantage in assisting starting of the engine by providing a fairly hot spark at low speeds. I

'While the form of mechanism herein shown and described constitutes a preferred form of embodiment of the invention, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

Vhat I claim is as follows:

1. In an ignition system for internalcombustion engines, the combination with a current source and an ignition coil having a primary winding of relatively low inductance and a secondary winding; of a. booster coil having a secondary winding in series with the secondary winding of said ignition coil, and a primary Winding of relatively high inductance; and engine operated make and break means for connecting the primary a primary winding of relatively low inductance and a secondary winding; of a booster coil having a secondary winding in series with the secondary winding of said ignition coil, and a primary winding of relatively high inductance, the transformation-rati of said booster, coil being lower than the transformation ratio of said ignition coil; and a timer for connecting the primary windings with the current source.

3. In an ignition system for an internalcombustion engine and an auxiliary device; the combination of spark plugs in said englue and device; an ignition coil includin r a secondary winding a booster coil inclu ing a secondary winding; said coils having their secondary windin in a series circuit with spark plugs in said engine and device; and means for varying the action of the 'l'oooster on the circuitwith changes in engine speed.

efiln an ignition system for an internalcombustion engineand a. fuel burner, means including a timer, a current source, and a plurality of ignition coils having different resistances intheir primary circuits, 'the primary windings of the coils being arranged in parallel and connected with the current source and timer.

5. In an ignition system for an internalcombustion engine and a fuel burner, means including a timer, a current source, and a plurality of ignition coils having different resistances in their primary circuits, the primary windings of the coils being arranged in parallel and in a circuit with the current source and timer and the secondary windings of the ignition coils being arranged in series.

6. In an ignition system, the combination with a primary ignition circuit including the primary windings of two ignition coils connected together in parallel and both together in-series with a current source and a timer;-of a secondary ignition circuit including the secondary -windings of said ignition coils connected cumulatively in series, an engine spark plug, means for consecondary windings, an

necting said engine plug with one of the secondary windings, and a burner spark.

plug connected to the other secondary Winding, said burner spark plug having a. gap wider than the spark gaps of the engine spark plugs.

7. In an ignition system, the combination with a primary ignition circuit including the primary Winding of an ignition coil of relatively low inductance and the primary winding of a second ignition coil of relatively high inductance, both of said primaries being connected in parallel and both together in series with a current source and a timer; of a secondary ignition circuit includingthe secondary windings of said ignition coils connected cumulatively in series, an enginespark plug, means for connecting said engine plu with one of the a burner spark plug connected to the other secondary winding.

8. In an ignition system, the combination with a primary ignition circuit including the primary winding of an ignition coil of relatively low inductance and the primary winding of a second ignition coil of relatively high inductance, both of said primaries being connected in parallel and both together in series with a current source and a timer; of a secondary ignition circuit including the secondary windings of said ignition coils connected cumulatively in series, an engine spark plug, means for connecting said engine plug with one of the secondary windings, and a burner spark plug connected to the other seconda winding, said coil of relatively low in nctance having a relatively high transformation ratio, said coil of relatively high inductance having a relatively low transformation ratio.

In testimony whereof I hereto aflix my signature. v

' JOHN H. HUNT.

Witnesses: H. E; Some,

.6. DALE Mum. 

